1126 
not shrivel up, however, as in the case 
of the black rot, and usually are easily 
detached from the bunch. The spores 
mentioned are produced in large num- 
bers and serve to spread the disease. 
The fungus causing this disease is 
closely related to that which produces 
the bitter rot of the apple. 
It is difficult to determine how much 
injury is done by this disease on ac- 
count of the liability of confusing it 
with other fungous troubles. It is quite 
generally distributed, and may cause 
more loss than is usually attributed to 
it. 
Treatment 
Spraying as recommended for black 
rot will largely prevent this disease The 
later applications are especially impor- 
tant and should be very thorough. 
Root Rot 
The roots of the grape are known to 
be attacked by several different fungi, 
especially when the root system has be- 
come weakened or injured by other 
causes. Three forms of root rot are of 
sufficient importance to be mentioned 
here. 
Vibrissea Hyprogaea 
This fungus is usually associated with 
insect injury, caused either by Phylloxera 
or by the grape root worm. It has been 
found in New York, Pennsylvania, and 
Missouri, and appears to hasten the death 
of plants, especially those on which the 
root worm has been at work. 
Treatment 
This root rot can be prevented only 
by the destruction of the insects which 
injure the root system and thus give 
the fungus opportunity to gain a foot- 
hold. 
Ozonium 
There is a root rot of a more serious 
nature prevalent in and chiefly restricted 
to Texas and New Mexico. This is caused 
by a fungus known as Ozonium, which 
also atlacks the roots of cotton and a 
great variety of other plants. It is most 
destructive in the black waxy, clay soils, 
which are very poorly aerated. Plants 
attacked die suddenly, 
the leaves and 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
{fruit withering up in a day or two and 
remaining on the vines. 
Treatment 
No remedy is known for this root rot 
of the grape. Soil upon which other 
plants have died with the same disease 
should be carefully avoided in planting 
vines. 
Armillaria Mellea. For description 
of this disease see Root Rot, under Ap- 
ple Diseases. 
References 
U. S. Department of Agriculture Farm- 
ers’ Bulletin 284. 
Duggar. Fungus Diseases of Plants. 
Rovenor. See Miscellaneous Diseases, 
this section. 
Shelling 
The shelling or dropping of grapes from 
the bunches before maturity may be due 
to various causes. In some localities in 
New York and Pennsylvania this trouble 
is rather serious. The cases which have 
been studied have been found to be due 
mostly to an imperfectly known fungous 
disease, which appears to be induced 
chiefly by improper pruning and train- 
ing Allowing the vines to produce too 
heavy crops is also likely to increase this 
trouble. 
Stem Cankers 
These are caused in many cases by 
freezes which cause dead spots, which 
become enlarged in healing. 
Drain the soil and prevent late growth. 
White Rot 
Contotherrum diplodiella 
The appearance of this disease is sim- 
ilar to the later stage of the downy mil- 
dew. Occurs in the Southwest and Ohio. 
It may be controlled by the same means 
as black rot 
MISCELLANEOUS DISEASES 
There seem to be a number of troubles 
of the grape, at present little understood, 
which have attacked the vines in Cali- 
fornia. 
Anaheim disease, also called the Cali- 
fornia Vine disease, was of the greatest 
importance a number of years ago when 
almost all the vineyards in Southern Cali- 
fornia died from a mysterious trouble 
